Resistor element



Nov. 22, 1966 R. A. scHAEcHER RESISTOR ELEMENT 2 Sheets-Sheet 1 Filed Sept. 6. 1965 wie.

R. A. SCHAECHER RESISTOR ELEMENT Nov. 22, 1966 2 Sheets-Sheet 2 Filed Sept. 6. 1963 INVENToR. Rohan/0,9, J'eAWZ//Ji -BY Zij 1 m4 fray/vips United States Patent Office 3,287,685 Patented Nov. 22, 1966 3,287,685 RESISTOR ELEMENT Roland A. Schaecher, Columbus, Nebr., assignor to Dale Electronics, Inc., Columbus, Nebr., a corporation of Nebraska Filed Sept. 6, 1963, Ser. No. 307,267 3 Claims. (Cl. 338-318) Wire-wound and film-type resistors characteristically have a cylindrical core with the resistive element on the outer surface thereof. A metal cap is normally placed on the ends thereof to serve a-s a terminal connecting means.

A principal object of this invention is to provide a resistor element which utilizes lterminal blocks that will greatly enhance the heat dissipating characteristics of the resistor core without the use of terminal caps, and particularly will accelerate the heat dissipation from the core to the chassis upon which the resistor element is mounted.

A further object of this invention is to provide a resistor element of a material that serves rto quickly dissipate heat from the middle of the resistor core without housing the entire unit in `a heat dissipating jacke-t.

A still further object of this invention is to provide a resistor element wherein the terminal or mounting blocks thereof will facilitate the-mounting of the resistor element to a chassis.

A still further lobject of this invention is to provide a resistor element which provides a terminal connecting means that will allow the resistance core to he rotated to any convenient angle within substantially 180 degrees of displacement.

A still further object of this invention is to provide a resistor element which will permit the core element to be finely machined so as to prevent the creation of hot spots after the resistance material is placed thereon.

These and other objects will be apparent to those skilled in 'the art.

This invention consists in the construction, arrangements, and combination, of the various parts of the device, whereby the objects contemplated are attained as hereinafter lmore fully se-t forth, specilically pointed out in the claims, :and illustrated in the accompanying drawings, in which:

FIGURE 1 is a disassembled perspective schematic view of one form of the device Iof this invention;

FIGURE 2 is an elevational view of the assembled components of FIGURE 1 with a resistance element and a coating secured thereto;

FIGURE 3 is a sectional view of the structure in FIG- URE 2 take-n on line 3 3 of that figure;

FIGURE 4 is .a schematic perspective View of the disassembled components `of a sec-ond form `of the device of this invention;

FIGURE 5 is an elevational view of the assembled components of FIGURE 4 with a resistance element and coating mounted thereon;

FIGURE 6 is a sectional view ,of the device of FIG- URE 5 taken on line 6-6 of that gure;

FIGURE 7 is a perspective view Vof a third form lof the base core of this invention;

FIGURE 8 is an elevational view of the core of FIG- URE 7 with a resistance element and coating mounted thereon;

FIGURE 9 is a sectional view of the device in FIG- URE 8 taken on line 9--9 of that figure;

FIGURE l0 is a perspective View of the disassembled components of a fourth form of this invention;

FIGURE 1l is an elevational view of the assembled component-s of FIGURE 10 with a resistance element and coating material thereon; and

FIGURE 12 is a sectional view through the device of FIGURE 11 taken on line 12--12 of that ligure.

With reference to FIGURE 7, the numeral 10 generally designates a resistor core base of integral construction and having an elongated cylindrical core portion 12 which has its ends terminating in rectangular terminal blocks 14 and 16. The material of the resistor core base 10 should have a high thermal conductivity such as that characteristic of beryllium oxide. A center bore 18 eX- tends along the longitudinal axis of the resistor core base and intersecting bores 20 and 22 in the blocks 14 and 16 serve as mounting holes. Screws, rive-ts, or other connecting means serve -to extend through the bores 20 or 22 to etiect the connection of the resistor core base to a -chassis means. As will be noted in both FIGURES 7 and 9, Ithe diameter of the cylindrical core portion 12 is less than either the width or the height of thel blocks 14 and 16.

Electro conducting band terminals 24 extend around the core portion 12 adjacent the ends thereof. These band 'terminals are welded upon themselves at 26 and protruding terminal ends 28 extend radially outwardly therefrom. A resistance ele-ment 30 which can be either wire, lilm, or other comparable substance, is located on the surface of the cylindrical core portion 12 and is connected to each of ythe terminal bands 24. A high temperature silicone coating 32 covers the resistance element 30 but the blocks 14 and 16 are exposed to the atmosphere. The coating serves only to protect Ithe resistance element from moisture and other environmental conditions. Terminal ends 28 are exposed to the :atmosphere as they protrude through the coating 32.

With reference to FIGURES 4 through 6 an elongated cylindrical core portion 34, which is similar in all respects to the elongated cylindrical core portion 12 of resistor ycore base 10, has an elongated center bore 36 extending along its longitudinal axis. Rectangular terminal blocks 38 and 40v have pairs of bores 42 and 44 extending therethrough in intersecting directions to serve as mounting holes in the same manner served by bores 20 and 22 in the terminal blocks 14 and 16 of resistor core base 10. Recessed bores 46 extend inwardly into the inner face 48 of terminal blocks 38 and 40. Smaller apertures 50 extend through the terminal blocks 38 and 4t) and are concentrically positioned with respect to the recessed bores 46. The diameter of the core portion 34 is less than the width or ther height of the terminal blocks 38 and 40.

The ends of the cylindrical core portion 34 are adapted for reception within the recessed bores 46 of the terminal blocks, as shown in FIGURE 5. Bolt 52 with head portion 54 and a Athreaded end 56 is inserted through the apertures 5G and recessed bores 46 of the terminal blocks and through the center bore 36 of the core portion 34. A nut 58 is affixed to the threaded end 56 of the bolt 52 to eifect the rigid lconnection of the terminal blocks to the -core portion 34. Band terminals 24A, protruding terminal ends 28A, resistance element 30A `and coating 32A are applied to the cylindrical core portion 34 in precisely the same manner as the corresponding ele-ments 24, 28, 30 and 32 were applied to the cylindrical core portion 12 of resistor core base 10.

A different means of mounting the elongated cylindrical core portion 34 is illustrated in FIGURES 10 through 12. There, a similar elongated cylindrical core portion 34A with a center bore 36A is supported by two mounting brackets 60. Each mounting bracket is comprised of a flat apertured horizontal shoe portion 62 which has a Vertical upstanding portion 64 secured thereto. The upstanding portions 64 terminate in a horizontal cylindrical portion 66. The cylindrical portion 66 of mounting brackets 60 are adapted for reception into the center bore 36A of the cylindrical core portion 34A. As shown in FIGURE 11, the lengths of the horizontal cylindrical portions 66 of the two mounting brackets 60 are such that they will not touch when inserted into the center bore 36A of the core portion 34A. The apertures in the shoe portions -of the mounting brackets are adapted to receive any convenient connecting means to secure the unit to a chassis support. Again, terminals 24A and terminal ends 28A, along with resistance element 30A and coating 32A, can be attached to the cylindrical core portion 34A in the same manner that they were attached to the cylindrical core portions 34. The mounting brackets 60 are preferably of the same material as the core portions 34A, and again the material of the mounting brackets and the core should be similar to that of the resistor core base 10, as described above.

With reference to FIGURES 1, 2 and 3, a solid elongated cylindrical core 68 has indentations 70 in the ends thereof for receiving the head and tail stocks of a wire winding machine. Rectangular terminal blocks 72 and 74 have intersecting bores or mounting holes 76 and 78 therein to effect the securing of the unit to a supporting chassis in the same manner that bores 20 and 22 serve in core base 10. Recessed bores 80 appear in the inner faces 82 of terminal blocks 72 and 74 and are adapted to receive the ends of the cylindrical core 68. The securing of the terminal blocks to the chassis support serves to hold the core 68 within the recessed bores 80. Terminals 24B, terminal ends 28B, resistance element 30B and coating 32B serve the same corresponding functions as elements 24, 28, 30 and 32 serve in regard to core base 10, as described above.

All of the cores and terminal blocks described are of the same or comparable high-thermal conductivity as core base 10. Thus, the terminal blocks of these units aid rather than inhibit the dissipation of heat from the core units, and the blocks especially assist in conducting heat from the cores to the supporting chassis. The chassis structures have been designated by the numeral 84 in FIG- URES 3, 6, 9, 11 and 12. The hollow construction of the core base permits heat to be dissipated therefrom on both its inner and outer surfaces.

The mounting or terminal blocks described serve as an effective means of securing the various units to these chassis structures. The core units and terminal blocks of the units in FIGURES 4, 7 and 10 are particularly adaptable for larger resistor units, and the device of FIGURE 1 is well suited for smaller designs. The transverse mounting holes in the terminal blocks allow some flexibility in the direction that the terminal ends 28, 28A and 28B will extend, and the rotatable characteristics of cores 34A and 34B further assist this phenomenon. Because of the use of beryllium oxide as the material for the core units, the need for a heat dissipating shell or casing around the unit has been eliminated.

It is therefore seen that this invention will at least accomplish all of its stated objectives.

Some changes may be made in the construction and arrangement of my resistor element without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims, any modied forms of structure or use of mechanical equivalents which may be reasonably included within their scope.

I claim:

1. In a resistor element,

an elongated core base of non-electro conducting material comprised of a cylindrical center portion having its ends terminating in rectangular blocks,

the diameter of said center portion being less than the height of said blocks,

mounting holes in said blocks,

a resistance element on said center portion and having opposite ends,

v a rst terminal band embracing said center portion and having a terminal end extending therefrom trans- 4- versely to the longitudinal axis of said center portion, said rst terminal band embracing said center portion between one end of said resistance element and one of said rectangular blocks,

and a second terminal band embracing said center portion and having a terminal end extending therefrom transversely to the longitudinal axis of said center portion, said second terminal hand embracing said center portion between the other end of said resistance element and the other rectangular block, said terminal ends of said rst and second terminal bands terminating in a plane outwardly of said blocks,

said first terminal band being operatively electrically connected to said one end of said resistance element,

said second terminal band being operatively electrically connected to said other end of said resistance element.

2. In a resistor element,

an elongated core base of non-electro conducting material comprised of a cylindrical center portion having its ends terminating in rectangular blocks,

the diameter of said center portion being less than the height of said blocks,

mounting holes in said blocks,

a resistance element on said center portion and having opposite ends,

a rst terminal band embracing said center portion and having a terminal end extending therefrom transversely to the longitudinal axis of said center portion, said first terminal band embracing said center portion between one end of said resistance element and one of said rectangular blocks,

a second terminal band embracing said center portion and having a terminal end extending therefrom transversely to the longitudinal axis of said center portion, said second terminal band embracing said center portion between the other end of said resistance element and the other rectangular block,

said rst terminal band being operatively electrically connected to said one end of said resistance element,

said second terminal band being operatively electrically connected to said other end of said resistance element,

said blocks having recessed bores formed therein which detachably rotatably receive the ends of said center portion, said center portion having an elongated bore on its longitudinal axis,

and a bolt means extending through said blocks and said center portion to secure them together and to prevent rotational movement of said center portion with respect to said blocks.

3. The resistor element of claim 2 wherein each of said blocks have at least two mounting holes formed therein and extending therethrough perpendicularly with respect to each other.

References Cited by the Examiner UNITED STATES PATENTS Re. 22,313 5/1943 Britton et al 338-318 X 228,123 5/1880 Sawyer 338-318 1,653,672 12/1927 Shriner. 1,694,178 12/1928 Hudson 338--269 X 1,935,163 11/1933 Parsons 338-302 X 2,075,876 4/1937 Von Wedel. 2,151,799 3/1939 Richter 338-318 X 2,329,588 9/1943 Burns 248-264 2,502,950 4/1950 Hugus etal 338-318 2,636,963 4/1953 Wakefield 338-302 X 2,675,453 4/1954 Ellin 338-302 X 2,694,765 11/1954 Hynes 338--318 X 2,773,159 12/ 1956 Taggart 338-302 X 2,777,926 l/1957 Bourns 338--322 X 2,954,539 9/1960 Blanco 338--180 X 2,963,539 12/1960 Hynes 174*138 (Other references on following page) 5 UNITED STATES PATENTS Melcher et a1 317--101 Sloop 248-205 Levy 338-302 X Schultz 338-316 Malnowski 13-25 Staer 219-239 6 FOREIGN PATENTS 12/1953 Denmark.

2/ 1959 Great Britain.

5 RICHARD M. WOOD, Primary Examiner.

V. Y. MAYEWSKY, Assistant Examiner. 

1. IN A RESISTOR ELEMENT, AN ELONGATED CORE BASE OF NON-ELECTRO CONDUCTING MATERIAL COMPRISED OF A CYLINDRICAL CENTER PORTION HAVING ITS ENDS TERMINATING IN RECTANGULAR BLOCKS, THE DIAMETER OF SAID CENTER PORTION BEING LESS THAN THE HEIGHT OF SAID BLOCKS, MOUNTING HOLES IN SAID BLOCKS, A RESISTANCE ELEMENT ON SAID CENTER PORTION AND HAVING OPPOSITE ENDS, A FIRST TERMINAL BAND EMBRACING SAID CENTER PORTION AND HAVING A TERMINAL END EXTENDING THEREFROM TRANSVERSELY TO THE LONGITUDINAL AXIS OF SAID CENTER PORTION, SAID FIRST TERMINAL BAND EMBRACINNG SAID CENTER PORTION BETWEEN ONE END OF SAID RESISTANCE ELEMENT AND ONE OF SAID RECTANGULAR BLOCKS, AND A SECOND TERMINAL BAND EMBRACIG SAID CENTER PORTION AND HAVING A TERMINAL END EXTENDING THEREFROM TRANSVERSELY TO THE LONGITUDINAL AXIS OF SAID CENTER PORTION, SAID SECOND TERMINAL BAND EMBRACING SAID CENTER PORTION BETWEEN THE OTHER END OF SAID RESISTANCE ELEMENT AND THE OTHER RECTANGULAR BLOCK, SAID TERMINAL ENDS OF SAID FIRST AND SECOND TERMINAL BANDS TERMINATING IN A PLANE OUTWARDLY OF SAID BLOCKS, SAID FIRST TERMINAL BAND BEING OPERATIVELY ELECTRICALLY CONNECTED TO SAID ONE END OF SAID RESISTANCE ELEMENT, SAID SECOND TERMINAL BAND BEING OPERATIVELY ELECTRICALLY CONNECTED TO SAID OTHER END OF SAID RESISTANCE ELEMENT. 